Thus, the aim of the present study was to explore relationships between the occurrence of OSA in individuals with obesity and ADMA and/or SDMA levels, as well as the effect of the endothelial nitric oxide synthase (eNOS) gene polymorphism, which may modify the influence of ADMA or SDMA on NO production. Here, NOS3 is linked to obesity due to melanocortin 4 receptor deficiency.